How to Seal Unglazed Tile

Unglazed tiles should be sealed with liquid tile sealant during the installation process, even if you want them to retain their flat look (sealants come in gloss and non-gloss finishes, just like paint). Grout will stain unsealed tile, so you have to seal the tile before grouting, then reseal it once the grout is in place.

1. Lay your tiles on the floor with tile adhesive, spread down with a notched trowel. Space the tiles 1/8 or 1/4 inch from each other. Cut the tiles at the edges of the floor as needed on your tile cutter. Let them set overnight.

2. Dip your paint brush into the can of penetrating sealer, wetting an inch or two of the tip. Slowly brush it onto the surface of the tiles, using short, even strokes in one direction. Don't brush it into the spaces between the tiles.

3. Let the sealant dry to the touch (an hour or two). Apply a second coat. Let it dry overnight.

4. Grout the tiles with your grout float (a flat rubber trowel), pressing the grout into the lines and squeezing it off the surface. Let it sit in the lines for 10 minutes, then wipe down the tile with a damp sponge to remove the excess grout.

5. Let the grout cure for a week. Re-coat the surface with tile sealer in the same manner as before, except cover the whole area, both tile and grout. Use two coats.

Warning

Ventilate the area when applying your grout sealant.